Sash balance



Aug. 12,- 1930. T. OHNO SASH BALANCE 'Filed July 25, 1e27 :Paa a as. 12.

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ccording to the present invention or ropes attached at both sides of thedoor are lead to .one side of the frame'through I guide pulleys ofssible friction and the other on of said chains or ropes hangingparallel each other are fastened separately. to a counter balance at twopoints each of which being equally apart from: the vertical centre ofsaid counter balance. By properly adjusting the length of one of saidchains or ropes the balancing forces acting respectively on both sidesof the window or door while at rest are.rendered equal so that theoperation of the door may be kept easy and smooth.

The invention is more particularly described with reference to theaccompanying drawing in which Fig. 1 is a sectional elevation of theinvention as applied to a window.

Fig. '2 is a sectional plan view of same. Fig. 3 is a sectional sideelevation at the part of the counter balance.

Referring to the drawing the. window frame (1) is provided at both sideswith vertical grooves and doors (2) (2) are slidably fitted therein.Said door. (2) is provided at its upper side with hooks (3) and (3) andchains 4) (4') are attached thereto at one and. T e other end of saidchains or ropes. are lead vertically upward and one of them (4)passingron a guide pulley (5 of a possible minimum iction is hung to abalance weight chamber (6) formed at one side of the frame (1). Theother chain or ro e (4') passin' on guide ulleys (5') and (5 is also leato said 0 amber (6) to be hun parallel to said chain (4). One of saichains, for instance (4), is directly connected at its lower end to acounter balance (7) and the other (4') is adjustably connected by m'eansof a screwed book 8) to the same counter balance 7Saidcha1ns(4)-and(4=') areseparately connected to the to of the counterbalance at two points-in sue a manner that each of as sa d points areequally apart from the vertical centre of the counter balance sothat-equal wei' hts may be distributed to the chains w hi e the door isat rest. By properly adj ustmg the length of one of the chains for inacstance (4') the door may be suspended by the counter balance equallat'both sides.

In the ordinary win ow'or door of the type hitherto in use the door issuspended by counter balances at both sides arranged ir as tive of eachother. When 0 ned or close the door is apt to be incline according tothe point of. ap lication of force and alternately strikes at t e bottomof the groove whic causes'the door to creak unless carefully op- 10erated by both hands or precisely at its centre. The 0 eration of thedoor can not be made smoot even for a narrow one. s

The resent invention is characterized in comparison with'those windowsor doors 76 hitherto known in that chains or ropes conneeted at bothsides of the door are fastened at the other ends to a counter balanceseparately at two points equally off the vertical centre of said counterbalance so that the door is always balanced horizontally and may beraised or lowered smoothiy irrespective of the position where the orceis applied. For instance the door is raised or pressed upward at itsleft/ side end. 'At theinstant of being raisedthe chain (4) at this sideis slackened and the door hecomes inclined in some degree. The counterbalance is thereby inclined owing to the slackness of the chain (4) insuch a manner that the centre of gravity of the counter balanceisbrought nearer to the extension of the tight side chain (4'). Thetensions of the chains (4) and (4) caused by the weight of the counterbalance (7) which has been distributed equally whi e at rest are nowdiminished on the slack side and increased on the tight side. Thisincreased tension'of the chain (4'2 overcoming the frictional resistanceo' the guide pulley (5') acts on the 10 attention. As the counterbalance is connected at its top to two chains separately, said rallel toeach other so that window to lift it a the right side m id tension incuntil it comes equal to the manual force a plied at the left side of thedoor. When' ese forces are rendered equal on both sides the doorrecovers substantially parallel to the groove and is raised verticallywithout causing any creak. Thus the door may be continuously raisedkeeping said manner of the counter balance and chains.

The door becomes inclined at the instant of being raised at one side dueto the frictional resistance of the guide pulleys. It is thereforenecessary for carrying out the present invention that the friction ofguide pulleys (5) and (5), especial] the latter (5') are possiblyminimized. urther, the guide pulleys are preferably not lubricated toavoid the adhesion of dust. In these views steel rollers (10) are arraned on the axles (9) of the guide pulleys 5) and (5) so that thebalancing action 1s rendered active and practical to obviate theinclination of the door at the instant of operation.

Accordin to the present invention the door is raised or oweredvertically irres ective of the part where the force is applied y approofwhere the force is applied to the I slidable element.

2. A counterbalance as claimed in claim 1 in-which the means forsecuring one of the flexible means to the counterweight is adjustable.

3. A counterbalance as claimed in claim 1 in which the points at whichthe flexible elements are secured to counterweight are at equaldistances from the vertical median plane of the counterwei ht.

In testimony whereo I have aflixed my signature. I

TADASHI OHNO.

riate balancing forces caused automatically 1y the inclination of thecounter balance. he window or door may therefore be opened and closedvery lightly and smoothlyby one handand at any part without need ofspecial chains are hung the balance mec anism is adapted to be arbut rand in a comparatively narrow s ace of the alance chamber. .The counteralance being hung at two points it can be inclined ical uctuation ofbalancing orce which may becaused by the pendulum action of the counterbalance is avoided. The invention may be applied to all kinds ofvertical slidin doors and is especially, adapted for broa and in whatmanner'the same is to be performed I declare that what I claim-iss- 1. Acounterbalance for a slidable element prevented fromswingin and aperiodmounted in a frame defining an openin having a compartment formedat one si e thereof comprising a pulley mounted over said compartment acounterweight in said com artment, and separate flexible means pass ngover said pulley each secured at one end to one of the opposlte sides ofsaid slidable element and to said counterweight, the points ofattachment of said flexible means to the counterweight being on o positesides of a ve'rticalmedian'plane of said counterwei ht whereby avertical movement of the sli able element is effected by the automaticinclination of the counterweight irrespective iao ieo

